【摘要】：本文以薄葉蘭Lycaste macrobulbon為試驗(yàn)材料,通過(guò)葉綠素?zé)晒鈪?shù)的測(cè)定和葉綠素含量的測(cè)定,對(duì)薄葉蘭不同光合器官光合特性作了研究;通過(guò)遮光試驗(yàn)測(cè)定氣體交換參數(shù)和葉綠素?zé)晒鈪?shù),研究了薄葉蘭適宜的光照條件;通過(guò)干旱脅迫試驗(yàn)測(cè)定光合速率日變化、可滴定酸含量晝夜變化和氣孔晝夜運(yùn)動(dòng)情況,研究了干旱脅迫對(duì)薄葉蘭光合生理的影響。研究結(jié)果如下:(1)薄葉蘭的光合器官葉片、假鱗莖、萼片均進(jìn)行光合作用,萼片下表皮存在氣孔,葉綠素?zé)晒鈪?shù)中有效光化學(xué)量子產(chǎn)量Y(Ⅱ)、電子傳遞速率ETR、最大光化學(xué)量子產(chǎn)量Fv/Fm的值葉片高于假鱗莖,假鱗莖高于萼片,表明葉片光合作用能力最大。薄葉蘭假鱗莖的總?cè)~綠素含量約為葉片17.9%,類(lèi)胡蘿卜素的含量為葉片的17.1%;萼片總?cè)~綠素含量約為葉片的3.1%,類(lèi)胡蘿卜素的含量為葉片的13.2%。葉片Chla/Chlb值為2.258,假鱗莖C hla/Chlb值為2.231,萼片Chla/C hlb值為1.04。(2)薄葉蘭光飽和點(diǎn)在400~500μmol·m~(-2)·s~(-1)處,光補(bǔ)償點(diǎn)在0~20μmol·m~(-2)·s~(-1)處,光飽和點(diǎn)、光補(bǔ)償點(diǎn)均較低。20%光照處理的氣體交換參數(shù)曲線高于40%光照處理高于10%光照處理,說(shuō)明薄葉蘭在20%光照條件下光合能力最強(qiáng)。薄葉蘭初始熒光F0、最大熒光Fm、最大光化學(xué)量子產(chǎn)量Fv/Fm的值三個(gè)光照處理差異不大,有效光化學(xué)量子產(chǎn)量Y(Ⅱ)、電子傳遞速率ETR、熒光淬滅qP的值40%光照處理高于20%光照處理高于10%光照處理。說(shuō)明40%光照處理薄葉蘭PSⅡ反應(yīng)中心光合活性最強(qiáng)。(3)薄葉蘭葉片凈光合速率白天正值,夜間負(fù)值,干旱脅迫下凈光合速率顯著降低,最大值為0.859μmolCO2·m~(-2)·s~(-1),對(duì)照組最大值為3.789μmolCO2·m~(-2)·s~(-1);干旱脅迫下氣孔導(dǎo)度值一直很低,在0~0.02mmolH2O·m~(-2)·s~(-1)之間,隨時(shí)間變化氣孔導(dǎo)度變化幅度不大,對(duì)照組薄葉蘭葉片氣孔導(dǎo)度隨時(shí)間變化呈單峰型曲線,最大值0.088mmolH2O·m~(-2)·s~(-1)。薄葉蘭葉片干旱脅迫組可滴定酸含量高于對(duì)照組,在白天的10:00與16:00無(wú)明顯變化,夜間22:00明顯降低,凌晨4:00又升高,而對(duì)照組葉片可滴定酸含量在日夜的四個(gè)時(shí)間點(diǎn)都無(wú)明顯變化,葉片總有機(jī)酸含量含量夜間未出現(xiàn)明顯增高,在干燥條件下誘導(dǎo)未有出現(xiàn)CAM植物酸代謝現(xiàn)象。薄葉蘭兩種處理氣孔的開(kāi)放率、長(zhǎng)度、寬度、密度統(tǒng)計(jì)發(fā)現(xiàn),兩種處理氣孔在白天和夜間均有不均勻關(guān)閉的現(xiàn)象,干旱脅迫組氣孔體積小密度大,氣孔開(kāi)放率在10:00與22:00差異不明顯,對(duì)照組氣孔開(kāi)放率晝夜變化較大。
[Abstract]:In this paper, the photosynthetic characteristics of different photosynthetic organs of Elaeagnus angustifolia Lycaste macrobulbon were studied by measuring chlorophyll fluorescence parameters and chlorophyll content, and the suitable light conditions were studied by measuring gas exchange parameters and chlorophyll fluorescence parameters by shading test. The diurnal variation of photosynthetic rate, diurnal variation of titratable acid content and diurnal movement of stomata were measured by drought stress experiment. The effects of drought stress on photosynthetic physiology of Elaeagnus angustifolia were studied. The results are as follows: (1) the photosynthetic organ leaves, pseudo-bulb and sepals of Elaeagnus angustifolia all carry out photosynthesis, there are stomata in the lower epidermis of sepals, the effective photochemical quantum yield Y (鈪，

本文編號(hào)：2504792